Save Silent Valley was a social movement aimed at the protection of Silent Valley, an evergreen tropical forest in the Palakkad district of Kerala, India. It was started in 1973 to save the Silent Valley Reserve Forest from being flooded by a hydroelectric project. The valley was declared as Silent Valley National Park in 1984. Nonetheless there is still controversy surrounding the valley.
The Kuntipuzha is a major river that flows 15 km southwest from Silent Valley. It takes its origin in the lush green forests of Silent Valley. In 1928 the location at Sairandhri on the Kunthipuzha River was identified as an ideal site for electricity generation.In 1970 Kerala State Electricity Board(KSEB) proposed a hydroelectric dam across the Kunthipuzha River that runs through Silent Valley, that will submerge 8.3 sq km of untouched moist evergreen forest. In February 1973, the Planning Commission approves the project at a cost of about Rs 25 crores.
After the announcement of imminent dam construction the valley became the focal point of Save Silent Valley, India's fiercest environmental debate of the decade. Because of concern about the endangered lion-tailed macaque, the issue was brought to public attention. Romulus Whitaker, founder of the Madras Snake Park and the Madras Crocodile Bank, was probably the first person to draw public attention to the small and remote area. In 1977 the Kerala Forest Research Institute carried out an ecological impact study of the Silent Valley area and proposed that the area be declared a biosphere reserve.
In 1978 Indira Gandhi, Prime Minister of India, approved the project, with the condition that the state government enact legislation ensuring the necessary safeguards. Also that year the IUCN (Ashkhabad, USSR, 1978) passed a resolution recommending protection of lion-tailed macaques in Silent Valley and Kalakkad and the controversy heated up. In 1979 the Government of Kerala passed legislation regarding the Silent Valley Protection Area (Protection of Ecological balance Act of 1979) and issued a notification declaring the exclusion of the hydroelectric project area from the proposed national park.